Year of Award


Document Type


Degree Type

Doctor of Philosophy (PhD)

Degree Name

Clinical Psychology

Department or School/College

Department of Psychology

Committee Chair

Stuart Hall

Commitee Members

Laura Dybdal, Christine Fiore, Craig McFarland, Tom Seekins


University of Montana


Traumatic brain injury is a serious public health problem in the United States, and cycling represents the largest category of sports-related head injuries. Helmets can significantly lower the risk of brain injury for cyclists of all ages. Yet, the incidence of traumatic brain injury as a result of a bicycle-related injury remains high. Due to consistently low base rates of helmet use in the college-aged population, this group is a prime target for research and interventions focused on bicycle helmet use behaviors. This research uses Prochaska and DiClemente’s Transtheoretical Model (TTM) of behavior change to examine bicycle helmet use behaviors in college-aged individuals. This study builds upon previous research to address all four constructs of the TTM (Stages of Change, Decisional Balance [Pros and Cons], Self-Efficacy [Confidence and Temptation], and Processes of Change [Experiential and Behavioral]). Questionnaires were administered to undergraduate psychology students in Spring semester 2015 and Fall semester 2016 at two universities in the northwestern United States (N=547). Chi-square tests for independence were conducted to analyze the relationship between bicycle helmet use and demographic characteristics, bicycle-riding behaviors, and past experiences. Three ANOVAs (with Tukey’s post-hoc analyses) and 3 Welch ANOVAs (with Games-Howell post-hoc analyses) were used to analyze the application of the constructs of the TTM to helmet use, and to permit comparison to the theoretical relationships predicted by the TTM model. Overall, the relationships among the constructs of the TTM were similar to those found when the TTM is applied to other health-related behaviors. The largest portion of variance among the 5 stages was derived from Processes of Change construct, followed by the Self-Efficacy construct, and then the Decisional Balance construct. Behavioral and Experiential Processes accounted for the largest magnitude of difference between the Precontemplation and Contemplation stages; Confidence and Behavioral Processes accounted for the largest magnitude of difference between the Preparation and Actions stages. These findings support future application of the TTM to conceptualize bicycle helmet use in college-aged individuals and to inform the development of helmet promotion interventions. Specific examples about how to modify helmet-related interventions based on the TTM are provided. This research contributes to the limited body of knowledge focused on the application of health behavior theories to understand bicycle helmet use.


© Copyright 2017 Julia Anne Hammond